I'm trying to put together a 7.1 surround sound system. For the front left, center, and front right I'm going to be using Athena WS-60s. They're 150watts, 8ohms. For the surrounds and surround backs, I'm going to be using 8" Phoenix Gold in-ceiling speakers. They're 100watts, 8ohms. And for the sub, I'm going with an Athena AS-P4100. This is supposed to be 400watts.

I recently read that running your speakers with an underpowered amp could actually damage them (unless of course, I'm misunderstanding). The receiver I'm considering is a Sony STR-DG910. This receiver puts out 110 watts per channel. I'm guessing this is ok for the 100watt Phoenix Golds. But what about the 150watt Athena WS-60s? And what about the sub? It's 400watts.

Would I be ok with going with that receiver with those speakers? I've already ordered the speakers, so I'm stuck there. The receiver is the only thing I'm still flexible on.

Thanks!

There's plenty of power in what you're looking at. The sub has it's own amp.

You'll be fine as long as you don't push the receiver past what it should be.

I’ve heard a JBL 4645 sub in the cinema being underpowered and the result was a damaged single sub that ended up making lots of popping sounds. Oh, this was years ago around (1998) Event Horizon (1997) and since then I think the cinema has installed x4 JBL professional subs not sure if there the newer 4645C hope they have the right amount of power this time around.

As for my JBL 4645 that too is being driven underpowered and I haven’t had any misfortune with it over the past 9 years. I intend to get it powered correctly soon to allow more freedom and headroom.

I’d keep a very close eye on the levels if you have any barograph display levels to look at because someday a real bad a$$ LFE.1 will come along and will bite hard on the sub.

They're 150watts
No, they aren't. You misunderstand the meaning of this spec. (And specs are important, if you understand what they mean.) What this spec means is that the manufacturer does not recommend using an amp greater than 150 watts/channel. So, as biff says, you're perfectly fine.

I recently read that running your speakers with an underpowered amp could actually damage them (unless of course, I'm misunderstanding).
There is some truth to this--amps struggling to drive a speaker can put too much power into a tweeter, for example. But your receiver is nowhere near that weak.

And for the sub, I'm going with an Athena AS-P4100. This is supposed to be 400watts.
Forgot to add that this is a whole different thing. The sub has an amp inside it, and it's that amp that delivers up to 400 watts (although that's peak power; it's really a 100-watt amp). Your receiver does not drive the sub at all, it merely delivers a signal to the amp inside the sub.

Great info. Thanks a lot guys!

Ironically, it'll be easier to damage a '150 watt' speaker with a 100 watt amp than a 500 watt amp. Speakers get damaged when an amp runs out of power and sends a clipped signal to the speakers. This is usually heard as a staticy, distorted sound.

As long as you don't go really crazy with the volume level (and if you start hearing your speakers distort at high volumes turn it down) you'll be just fine.

Ironically, it'll be easier to damage a '150 watt' speaker with a 100 watt amp than a 500 watt amp. Speakers get damaged when an amp runs out of power and sends a clipped signal to the speakers. This is usually heard as a staticy, distorted sound.

As long as you don't go really crazy with the volume level (and if you start hearing your speakers distort at high volumes turn it down) you'll be just fine.

That would be where the signal goes from [sine wave to square wave] correct me if I’m wrong been a while since I read any manuals.

Ironically, it'll be easier to damage a '150 watt' speaker with a 100 watt amp than a 500 watt amp.
This is not strictly true. It's easier to damage one with a 10-watt amp, for sure. But a 100-watt amp will not clip sufficiently to damage a speaker like that (assuming the specs are reasonably accurate).

I recently read that running your speakers with an underpowered amp could actually damage them (unless of course, I'm misunderstanding).

No, the problem that you can run into is that one can push the amp into high THD/clipping and the resault of that can be damage to a speaker. If you do not over drive the amp you will be fine.

i love this place

Sorry for the bump.

Real quick though: I have speakers with a 120w max recommendation and a receiver with a 170w rating and the receiver keeps flashing "PROTECT". I think this is a simple solution that I can't figure out on my own and you guys seem like pros so please, what can I do to keep the receiver from cutting out? Do I have to purchase anything?

Help a n00b out!

Sorry for the bump.

Real quick though: I have speakers with a 120w max recommendation and a receiver with a 170w rating and the receiver keeps flashing "PROTECT". I think this is a simple solution that I can't figure out on my own and you guys seem like pros so please, what can I do to keep the receiver from cutting out? Do I have to purchase anything?

Help a n00b out!

Some possible reasons--

Listening at too high a level for too long.
Receiver is not getting adequate cooling.
Speaker impedance is too low for your receiver (as load impedance fails the amplifier more power is drawn).
The light for the protection circuit comes on too soon.


If you need more please tell us the make and model of your speakers and receiver. The best idea you can give of the volume setting when the light flashed. The kind of program material (rock for example often has a limited dynamic range so the average power level stays high). Whether or not there was audible distortion, thumping or other unpleasantness heard before shutdown.

receiver keeps flashing "PROTECT".
If would help if u tell us how often this happens and only during high volume? And do you have this setup for a long time or new setup?

Thanks for replying. It happens at low volumes as well as high, but too often we can't even get to a high volume level before it happens. The receiver is getting plenty of ventilation so it's staying cool.

This is a new setup, kind of. New speakers with an old receiver. It's a Sony STR D515 receiver and new Sony SS B3000 speakers (yes, I know they're cheap but I hope that's not the problem). The issue happens when listening to anything, electronic and rock. They sound great, with no distortion or anything then all of a sudden it switches to protect.

Specs

Receiver: 120 v, 60 Hz, and 170 w
Speakers: 50kHz max and 120 w max input power

Are my speakers sending a bad signal to the receiver? Should I get a preamp in between the two? Am I just using buzz words and don't really know what I'm talking about?

Are my speakers sending a bad signal to the receiver? Should I get a preamp in between the two? Am I just using buzz words and don't really know what I'm talking about?
Yeah, that one. :)

Speakers don't send signals to receivers, and preamps don't go between receivers and speakers. (Receivers contain preamps.)

Specs

Receiver: 120 v, 60 Hz, and 170 w
Speakers: 50kHz max and 120 w max input power
These make little to no sense. If that's all the spec sheet says, then the spec sheet is meaningless. (And there's probably a reason for that.)

This is a new setup, kind of. New speakers with an old receiver. It's a Sony STR D515 receiver and new Sony SS B3000 speakers (yes, I know they're cheap but I hope that's not the problem). The issue happens when listening to anything, electronic and rock. They sound great, with no distortion or anything then all of a sudden it switches to protect.
The simple answer is that your speakers are, at some point, presenting to big a load to the amplifier. What were you using for speakers before? My first-cut advice would be to return the speakers and find something else. But I'd also consider the possibility that the old receiver just can't get it up anymore.

Thanks for replying. It happens at low volumes as well as high, but too often we can't even get to a high volume level before it happens. The receiver is getting plenty of ventilation so it's staying cool.

This is a new setup, kind of. New speakers with an old receiver. It's a Sony STR D515 receiver and new Sony SS B3000 speakers (yes, I know they're cheap but I hope that's not the problem). The issue happens when listening to anything, electronic and rock. They sound great, with no distortion or anything then all of a sudden it switches to protect.

I think you need to check your speaker wire connections very closely for bad connections or loose strands of wire that may be shorting out. Check at the receiver end and at the speaker end.

Also, it's not a bad idea to check the entire length of the speaker cables to ensure they are not damaged and possibly causing an intermittent short.

Most common cause of it shutting down into protect is a short. Disconnect each speaker completely at both ends and reconnect carefully making sure it's not shorted to the chassis or anything else. It only takes one tiny strand.

Make sure you have proper ventilation and the receiver isn't overheating. If possible measure the resistance of the speaker drivers and see if they're blown/shorted, and also the speaker wire to make sure it's not damaged.

If still no remedy, hook up each speaker one by one to try to isolate a speaker-based fault.

The speaker cable is stock, whatever came with the speakers. I wanted to buy some better stuff but haven't gotten around to it, and I also have troubles believing that's the issue.

But I'd also consider the possibility that the old receiver just can't get it up anymore.

This is probably more like it, in which case, it looks like I'm in the market for a new receiver.

Thanks for all your help, guys!

Yup. Probably a good idea to buy a new receiver before you do something simple like check the speaker wires and do a process of elimination. :rolleyes:

I found this while googling to see if my 50w/ch Klipsch amp would kill my Sony B3000's, although I didn't even type Sony into the search... I broke my Energy C100's in with the amp and they seem to be ok so I'm not too worried. After about 25 hours I'll put the Sonys on my Onkyo 606. I've been listening to static and playing at pretty low volume, some nice classical masterpieces haha.

Anyways the included speaker wire, I'm using it with the Klipsch (Onkyo has 12awg waiting), is something like 22awg. Used with a higher powered receiver I could definitely see it being an issue.

Speakers are damaged by either exceeding their thermal limits, or their mechanical limits.

Mechnical limits you can probably hear when you overdrive your woofer. I have done this, and it's not subtle.

Thermal limits means the voice coils overheat from excessive power.

How much is excessive power? In theory a speaker's specs define how much power it can handle. But I have heard the accuracy of those power measurements questioned.

Tweeters can't handle much power. They have small voice coils with limited heat dispersion capacity. They also get a lot less power.

When you overrive your amp, the average power level increases faster than you might think because the wave forms are now distorted to look more like square waves rather than nicely rounded sine waves. A 100 watt amp which is measured assuming waves are sine wave like, using RMS, will put out much more power (when it starts clipping.)

It's not the clipping itself which damages the speaker, it's likely the thermal load caused by the higher average power the clipping causes.

So a 10 watt amp could be turned up to max power, and it might not blow your speakers because it does not have enough power.

In the same way, a very high power amp could damage low power speakers even when it's not clipping. Because it's power which equals heat which destroys a lot of speakers.

However, a high powered amp will also be harder to clip, so some people recommend more amp power than speaker power handling capability.

I assume that an amp could also damamge a speaker by hitting it's driver's excursion limits too often.